Demon Baby Daddy
by Girl with the Iceheart
Summary: It shouldn't have happened. It was wrong on so many levels. But here they were; Rin was pregnant and there was a high chance he could die along with baby and/or be discovered by the Vatican. Oh, and on top of that, he wasn't exactly sure if it was his twin, his ex-enemy or his principal that got him pregnant. Great... (Actually written seriously, not as bad as it sounds). On hiatus
1. Normal Day

Demon Baby Daddy

Chapter 1: Normal Day

 _A/N: I'm sorry this just popped into my head so uh here you go. This chapter is kinda long and slow, just trying to set the scene; I swear the other ones will be much more fast-paced. Also this is set in the anime universe for the pure purpose of demon Yukio. Btw no lemons/smut scenes because I'm not so confident in my smut writing and also to keep the T rating on this fic (BUT if I am feeling up to it, I'll post it as a separate section on ao3), but there are_ _ **heavy**_ _implications throughout._

 _Imma just say it here and now rather than later so: You clicked the link knowing what was in store so don't come complaining if you don't like mpreg/yaoi._

* * *

Rin awoke groaning and shifted over, feeling disorientated. With a yawn, he noted he was in his dorm room, judging by the harder bed and rougher sheets. Flinching slightly as he turned over, he huffed throughs his nose and frowned, trying to order his thoughts.

"You're up."

Rin blearily opened his eyes and blinked, trying to clear his vision. When the mist cleared he was greeted by the sight of his twin brother watching him from his seat at his desk.

"Are you feeling alright? Not too sore?" Yukio asked calmly like it was the most normal thing in the world to ask his brother. Out of context it might've sounded innocent, but it wasn't in the least. Rin huffed and pressed his face into the pillow, groaning. He heard an amused laugh from Yukio, only aggravating him more, "I'll assume that's a no".

"Damn right you moley four eyes," he hissed when he tried to sit up, rubbing his back. "Might be alright for you but it is bloody painful for me!"

Yukio stood up and began packing his bag, "It must be truly painful if it was to enough rouse you this early. I wonder if Amaimon is experiencing similar pains?"

Rin snarled, "He's probably fine thanks to his god damn accelerated healing."

Yukio closed his bag and began to walk to the door. "Make sure you start getting ready soon," he said and disappeared down the hall.

Rin shakily got to his feet, wincing. Damn demon brothers. He wobbled his way down the hall to the washrooms and to a shower, turning on the hot water. He hadn't been able to shower the night before, before falling asleep and he could feel the stickiness of sweat still on him. Undressing from his trackies (he suspected Yukio was responsible for dressing him), he stepped into the shower and leaned an arm against the wall, resting his head into the crook of his arm. He exhaled as he reflected over the past few months, leading up to now.

It honestly shouldn't have happened. It was wrong on so many levels. It had started out so violent and unsteady; Yukio and Rin just mending together their sibling relationship after Yukio's demon blood was awakened, Yukio feeling mistrust to Mephisto over he's plotting, while Amaimon and Rin were quite literally at each others throats. But then, Mephisto, the damn clown he was, had decided that the four sons of Satan should start getting along. So after multiple unimaginably awkward 'family outings', with tense silences and Rin and Amaimon glaring daggers at each other, things finally started working. Rin and Amaimon had bonded over mock-fighting, originally vigilantly supervised by Mephisto.

With Amaimon and Rin having formed a friendship, the trips became much more frequent, more enjoyable. Yukio and Mephisto began to relax and Rin and Yukio were able to properly reform their previous closeness. Yukio and Mephisto began to form a friendship over their continued attempts to keep their destructive brothers in check. Mephisto had gradually become even more extravagant in his action towards the twins, which Amaimon had assured them, was Mephisto's final barrier before finally becoming comfortable with others. Yukio and Amaimon had also formed a much weaker (in comparison to the other) friendship, more like a friend-of-a-friend sort of relationship.

For a couple of weeks everything was fine. Nothing was going wrong and there were no foreseeable problems. Rin was improving in Cram school thanks to conversations with his two older brothers, much to Izumo's and Bon's surprise (it had been a sort of mutual agreement to keep the new-found friendships under wraps). Yukio had learnt proper control over his new powers thanks to all three brothers. According to Mephisto, Amaimon wasn't so insufferable now because he got to have regular battles with Rin.

But then everything went wrong...

Rin stepped out of the shower, now clean, and made his way back to his room. After dressing quickly, he made his way downstairs to where Kuro and Yukio were eating. Rin could hear a clatter from the kitchen indicating Ukobach was in the kitchen, cleaning up probably.

" _Rin!_ " Kuro yowled in delight on sight of the raven haired boy. Ukobach chattered his hello from the kitchen.

As Rin slid into his seat next to Yukio, being the moley four eyes he was, asked, "Feeling any better now, Nii-san?"

Rin flinched slightly at that as Kuro gave a curious tilt of his head, " _What happened? Did you get hurt yesterday?_ "

"N-no! Nothing like that!"

Kuro meowed like an ordinary cat but to them they heard " _Then why would you feel better?_ ". Rin silently cursed the little inquisitive cat. Wasn't he supposed to one hundred and twenty one? He acted more like a six year old human child.

"Uh y-yeah! I did lot's of rigorous training yesterday!" Rin had to hold down a flinch at his own wording. Baring his fangs slightly at his bespectacled brother's smirk, he slammed his heel down onto Yukio's toes. It wasn't like he was lying! Amaimon had been more aggressive in his attacks in their sparring yesterday, forcing Rin to work harder. Though that wasn't what made Rin sore...

Fortunately, the little cat demon seemed to miss the yelp and accepted the reason. Giving a little jump, he chirped " _We haven't played in ages Rin! Promise me we'll train tonight!_ "

Rin nodded and dug into his breakfast. Yukio took his tray up to the counter, giving his thanks to Ukobach on another excellent meal. Grabbing his bag, he waved goodbye, leaving the two demons to finish their breakfast.

Rin glanced over at Kuro and felt a twinge of guilt. He loved Kuro and hated having to sneak around and make excuses to the honest and sweet little Cait Sith. However all four had agreed it would be in everyone's best interests to keep things quiet... as in dead silent. Rin trusted Kuro but he wasn't sure how he'd take it if he found out. Also he wasn't sure how well the twin-tail could keep a secret.

Quickly finishing the meal, Rin galloped upstairs and gathered his things, slinging the Kurikara over his shoulder. As soon as he opened the door he was greeted by a little lime coloured hobgoblin with a black harness.

"Behemoth!"

Rin knelt down to give the little demon a scratch behind the horns, receiving an affectionate growl in return. His little burgundy tail started waving about happily, reminiscent of a dog, and began salivating even more. Amaimon had told Rin that Shura and Angel had exorcised him when he had stormed the Vatican in search of Rin (ahh good times!) and Rin was secretly glad the dog-like demon hadn't died... he was cute in his own way, kinda like a pug! (Rin had a sneaking suspicion that was what Behemoth possessed)

Rin tilted his head to the side. It was odd seeing the familiar without his green haired master. "Where's that broccoli head eh?" Behemoth gave a jolt, as though remembering something and leapt up and down on his stumpy legs. He extended his paw and in it was a small note written in frightfully bad hiragana that could only belong to Amaimon.

 _6:00 or as soon as can_

Rin almost sighed at the awkwardly written katakana that spelt out Amaimon's name. He wasn't the best reader or writer himself, barely able to read common kanji, but his 'older brother' hardly had any grasps on the Japanese letters.

The raven haired gave a small jump when he noticed Behemoth was still there. Giving a quick thumbs up to signal his thanks, the hobgoblin grinned widely and waddled away at a rapid pace.

Rin began making his way to school, his thoughts swirling for the third time that day.

When Amaimon and Rin first started their play-fights, Mephisto had created their own arena in which to use at their will. It changed every time they went, sometimes becoming a forest, sometimes a post-apocalyptic city; at one point it had replicated Mephiland (it was only later that they both realised it had been to celebrate the three month anniversary of their first encounter)! There was a safe viewing area Mephisto used to supervise or when Yukio would come to watch every now and then. Mephisto had made the strict rule of no fighting outside of the arena otherwise they'd both be paying out of their allowances; accompanied by a no flames/earthquake rule. He'd also had taken it upon himself in the beginning to watch their fights, to intervene if things got too out of hand; such as a couple of instances in the beginning. But he had decreased in his visits until recently he stopped all together.

Rin arrived in class, forcing himself to tug himself out of his thoughts and set himself up for a bored five-period school day just like usual.

* * *

After the normal class, Rin went to his usual door, fitted the key and stepped into the cram school hall. He gave a slight sniff of the dark unlit halls. He always preferred them to the waxy halls of the normal school. The exorcist school hallway smelled nicer, fresher. He guessed it was probably the herbs seeing as a class for third years trying to attain title of Doctor was right next to him. With a twitch, he caught a more flowery scent and turned to look down the hall.

"Rin!"

The ever cheerful Shiemi picked up her pace to jog over to Rin, smiling brightly. Nii greeted just as bubbly as its master, waving a fuzzy green arm and grinning toothlessly from his spot on Shiemi's headband. Rin grinned at his best friend. "Shiemi! How are ya?"

The blonde smiled and swung her bag happily, falling in to step with Rin as they made their way to their classroom. "I'm alright! My gardens are doing great! How are you and Yuki-chan?"

The rest of the school day blended. He remembered falling asleep to be sharply woken by Yukio slamming a book next to his head. He remembered Bon tching at his lack of conviction in training. He remembered him and Shima laughing over some dirty joke. An extremely normal day for Rin.

Then at the end of the day, Shima invited Rin to head into town with him and Miwa. Rin had at first lit up. Fantastic! He hadn't been able to hang out with the boys for a while! But...

"Sorry Shima," He said wincing slightly, "I promised a friend I'd meet up with him..."

Shima shrugged before snapping his head up and narrowing his eyes slightly. "What other friend? You've never mentioned other friends before. Are you av- OH!" the pinkette gave a gasp before leaning in, glancing from side to side, "do... do you have a girl? Is that who you keep disappearing to see?" he whispered with a grin. "Is it Moriyama-san?!"

Oh shit. Rin gulped, not knowing what to say. He didn't have 'a girl' per say. More three brothers... "Uh..."

"Is it Paku-chan?" Shima gasped and proceeded to invade Rin's space even more, "is it Izumo-chan?!"

Rin shook his head, glancing around. There just _had_ to be some way to escape...

"So? Who is it?" Shima asked eagerly, "is it a girl in the normal classes?"

"Umm! I uh got go!" And with that Rin bolted.

He leapt down the hall, ignoring Shima's yells and threw himself through the first exit door. Popping out in the school's lab hallway, yanking a key out of his pocket. It was silver and looked menacing with its axe shaped lock pattern. Shoving it into the closest door, he pulled it open and shot through. He fell onto his front with an oof, unbalanced by the suddenly rougher ground.

 **SLAM**

"You know you really shouldn't pose like that if you just want to fight today."

Rin shot his head up to see the demon King of Earth leaning against the now closed door, rolling a lollipop in between his lips. Flushing at realisation of his position and Amaimon's half lidded gaze, he got up glaring. He dusted himself off, purposely avoiding making eye contact.

The raven's face reddened again at the feeling of a pair of slender arms wrapping around his waist. Amaimon buried his head into the crook of Rin's neck, inhaling deeply.

"I missed you."

Rin sighed and returned the embrace. "We saw each other only last night!" At first he had been quite disconcerted by Amaimon's extremely affection, especially after the effects of the 'Event' had worn off, but the demon prince had little concept of space. So Rin had come to accept the Amaimon's hugs, kisses and obscure little gifts.

Amaimon purred and nuzzled his neck at the mention of the previous night. "You were so sweet last night," he mumbled, causing Rin to blush a brilliant red. He leant up to lick the raven's ear, "Wanna have an encore?"

Rin quickly shook his head, trying to dissipate the heavy blush. "S-sorry but I'm still sore from last night."

Amaimon let go at that, thankfully. Rin was glad that though Amaimon was more animal in nature, he never insisted and always backed off immediately. It wasn't like Mephisto or Yukio would harass Rin, no, they respected him, but they were always more reluctant to abate.

The green haired demon strolled his way into Rin's vision, flicking the stick of his lollipop into the grass. He then turned his intense cerulean eyes on Rin, lifting a fingernail up to chew. If it hadn't been for the fact that Rin had known him for so long, he would probably have missed the little clues of Amaimon's mood. Chewing his nails meant he was interested. Staring at him with such intensity was Amaimon's sign of undivided attention. He rarely voiced his emotions, more signalled them, like how a dog would wag its tail in happiness or a horse would flatten its ears in irritation.

"You ready?"

"Sure."

Rin had little chance to react as the demon King of Earth launched himself at him. Rin brought his arms up to block the blow and instantly Amaimon's face lit up, grinning a mouth of fangs and laughing in pure, childlike delight. Rin momentarily paused, staring.

He still wasn't quite used to Amaimon's sudden change in facial expression. One minute he'd be sporting a deadpanned expression, the next smiling with dazzling white fangs that never suggested his hyper sugary diet. It always left Rin a little stunned.

Amaimon, quick as always, bent down to sweep kick Rin's legs from underneath him. With a yelp, Rin went plummeting, only then remembering he still hadn't taken the Kurikara off. Sliding it out it's covering with practised ease, he swang it at Amaimon's head. Just because there was the 'no flames' rule, didn't mean Rin couldn't use his sword.

Catching the dark blue sheath, Amaimon swang him up and they both began to battle in the freshly generated hills.

* * *

One hour and several destroyed hills later, the two demons stood panting, staring at each other. With a single nod, they relaxed their stances and approached each other. Amaimon's face relaxed back into his usual neutral, already a lollipop in his mouth. Rin on the other hand, smiled and wrapped an arm around his neck. "You're getting better still!"

Amaimon stared at him, "You're progressing well yourself."

Rin grinned sheepishly, somehow a little flustered at that comment. In retrospect, it was silly that he would still feel embarrassed by a little comment like that, seeing as he had done much more 'embarrassing things' with the King of Earth (many were, not-so-surprisingly, suggested by Mephisto).

Lighter eyes bore into him. "Your face is red. Did you exert yourself too much?"

"N-no!" he said quickly flapping his hand (much to Amaimon's subtle confusion at the gesture). Though now that he mentioned he was starting to feel light headed... "I best be getting back to my dorm anyway."

Amaimon nodded and began to saunter away, crossing over to one of the multiple doors. Glancing back over his shoulder, he called out "See you later then," and disappeared down the door.

Rin gave a puff of relief to be finally alone for the first time in hours. He raised a hand to his forehead and frowned slightly. He supposed he just hadn't had enough time to rest. It had been a good while since he had a good rest, in between school, missions, Amaimon's sparring, Yukio's long study sessions and whatever wild shenanigan Mephisto had thought up for the Exwires, he hardly had any time to rest. As much as he cared for the three, they were a strenuous bunch...

Tracking down the casing for the Kurikara, he began to make his way back to the dorm. Going through his first door, he found himself warped a short walk from the dorm. Checking the overcast sky, Rin picked up the pace, hoping to beat the oncoming storm.

Much to his mixed surprise, as he approached the old dorm building, a certain person in almost offensively bright white stepped out. What was the clown doing there? Rin gave a wolfish grin when he saw the way he staggered slightly.

"Eyy Mephi!" he called out, startling the older demon.

Mephisto's green eyes widened and he jolted slightly, before relaxing at realisation it was only the raven-head. "Oh it's just you. For a moment I thought I had been found by Kirigakure-sensei," giving a mischievous grin, he nodded back to the grey dorm building. "I was just visiting Yukio."

Rin snorted, laughing. "Yeah, just 'visiting' hehehe!" he joked, poking Mephisto's side.

"Oh?" Mephisto's gave fastened onto the blue eyed boy's slightly tousled appearance, "been with Amaimon have you?"

"What?!" Rin's voice cracked at the implication. "We only sparred!"

" _Only_ sparred?" He purred, leaning down.

"Yes!" Rin squeaked.

Mephisto laughed and glanced skyward to where rain began to sprinkle. Opening his umbrella, he began to walk away, signalling the end of the conversation. Rin was about to sprint to the cover of the dorm when he heard the older demon pause. Looking back, Rin was greeted by piercing emerald green eyes, watching him with scrutiny.

"You look flushed. Are you feeling unwell?" Rin shrugged. "Hmm... take care then..."

Rin had to quickly turn and run to the door as it began to bucket, not missing the popping sound of the King of Time activating his power. Swinging open the door, he nearly collided with Yukio. He grinned mischievously and flung an arm around his twin's shoulder, laughing. "Got lucky did we?"

"Nii-san!" Yukio practically screamed.

Rin burst out laughing at the mortified expression on his brother's face. "Bwahaha! I met Mephisto on my way back~! Besides you reek of him," He said giving the brunette a sniff. Yep, definitely. Mixed into his usual gunpowder scent, was the unmistakeable candy floss and some kind of incense smell that clung to the purple-headed demon.

Yukio shivered at the close contact, his pointed ears twitching. Grabbing Rin's arm, he lifted it up his head, detaching himself from the one-armed embrace. Rin pouted slightly, looking slightly rejected. Sighing, Yukio leant in to peck him on the cheek. Immediately Rin brightened and turned, catching his brother on the lips.

Yukio's ears turned crimson, causing Rin to laugh harder. It was almost surprising at how easily Rin could make his bespectacled brother blush, but as soon as they reached the bedroom, the tables turned. However, before they could continue, there was a quick pittar patter of tiny feet.

" _Rin!_ "

Moving away from Yukio, Rin scooped up the little cat demon, cuddling him to his chest. "Hey Kuro! You had fun today?"

" _Rin it's raining..._ "

"Hmm?"

" _We can't_ _go play now..."_

Oh yeah, he had promised the Cait Sith that would go train tonight... With a grin he shook his head. "If you can ignore a little water, I'm game!" Well, a _little water_ was a bit of an exaggeration of the almost storm outside.

Kuro's mouth opened in the equivalent of a kitty gasp. _"_ _Really Rin?!"_

Rin nodded and the two bounded outside, leaving Yukio in the hallway, a warning to come in before they got sick on his tongue. Yukio sighed and pushed up his glasses. He was truly a most troublesome brother sometimes...

* * *

The next morning, Yukio awoke at his usual time and began to go about his morning routine. It was a Saturday, though Yukio had papers to grade, homework to do and other academic duties. His plans were disrupted however, when he began to go upstairs to begin his paperwork, he heard a frantic telepathic cry. Rushing to the door, he found Kuro batting at Rin's face, looking utterly distressed.

 _"_ _Rin! Rin! Wake up!"_ the cat demon wailed despairingly.

Yukio rushed over and saw to his horror, Rin out cold, pale white and drenched in sweat.

"Nii-san!"

He began to shake the older twin, only receiving a tired groan in response. Yukio started to panic. It could be a fever, but it looked much worse, like he was experiencing chronic pain. Yukio stood up and in his stricken mind, the first cause of action was to rush to the door, ram a key in and jump through.

"Mephisto! Amaimon!" he bellowed, running into Mephisto's office.

Amaimon, who had been hanging upside down while eating, widened his eyes ever so slightly at the sudden intrusion. He dropped to a crouch on Mephisto's desk and stared at Yukio, "What's the matter?"

"Rin's sick! He needs medical attention now!"

Amaimon popped himself up and mumbled something, his eyes going vague for a moment, before snapping back to attention. He jumped off the desk and pulled out his own key, hurrying to a door. Yukio dimly recognised it as an Infinity Key.

Shoving it into the door, Amaimon flung it open and yelled "ANIUE!"

One of the doors down the now accessible hallway opened up, Mephisto popped his head out the door, looking disgruntled. The purple haired demon caught sight of their expressions and made a beeline for them, cape billowing behind him.

"What is it?"

Yukio frantically wrung his hands, eyes darting to the door still open to their dorm room. "Rin's sick and it looks bad," he huffed.

The trio went straight for the magically opened door to the dorm, though Amaimon hung back to watch from the doorway, chewing on a nail. Mephisto was at Rin's bedside in an instant; Kuro jumping away upon realising it was the King of Time. Mephisto gently picked up Rin's arm, feeling his pulse, while the other hand checked his forehead. With a frown, he carefully pulled the sheets back and checked on the raven's tail.

It was limp, the usually silky black fur was coarse and it was cold to the touch.

"Shit..."

Yukio flinched at the curse. It was a beyond ominous sign if the principal was using such language.

The eldest demon whirled around to face the open door, staring straight at Amaimon.

"Get the chalk."

Amaimon was gone in a flash but not a moment later, held a packet of chalk used for drawing up summoning circles. He tossed them to Mephisto and began closing the windows, plunging the room into near darkness.

"What are you-?"

Mephisto gave a hiss for him to be silent, Amaimon grabbing his shoulder and pulling him to door. "He needs to concentrate for this..." he muttered while completely taking off a nail in his chewing.

"Doing what?!" Yukio hissed.

Mephisto had already drawn up a perfect summoning circle, freehanded, and was beginning to write archaic symbols... to restrict an extremely high level demon.

Amaimon's hand crept down to talk hold of Yukio's. Yukio glanced at the green headed demon, seeing him now chewing his lip nervously. The very human gesture of seeking reassurance seemed so incredibly foreign, coming from the mostly emotionless demon king. He was beyond nervous. Frightened even...

Yukio squeezed his hand.

Mephisto began to chant, his words sounding German in origin, and the pressure began to rise. Rin tossed slightly in his bed, moaning, completely unaware of the ritual happening less than a foot from him. As the dark versus began to take form, the summoning circle began to glow. If it wasn't for that fact that Yukio was holding Amaimon's hand, he would have missed the slight tremble from the demon prince and him moving to stand further back into the office, hiding behind Yukio. What the hell was he going to summon?

As the last syllable poured from the oldest demon's mouth, a figure made of smoke began to form.

* * *

 _A/N: Wow this got long (nearly 4 thousand words jesus christ!), so I decided to leave it at a cliff-hanger. So basically I've only got a vague idea of where this is going. I've only got a few angst/fluff ideas so far... read, review, follow, like and enjoy!_


	2. Results

Demon Baby Daddy

Chapter 2: Results

 _A/N: This chapter will definitely be shorter, I'm sorry about last time. (coughs) thanks for all the reviews and here are a couple of responses:_

 _To the_ _ **guest**_ _who sent me all those suggestions and guides: thank you! It's a little daunting getting those long emails ^_^" and I did do some research before beginning this story, since this is my first time writing something like this. I give a partial response in this chapter and a more in-depth response in chapter 4 or 5, but I will try and answer any questions about the whole-mpreg-anatomy thing. Also your story sounds interesting and don't worry about locking stories up ehe I've got hundreds of unfinished stories hidden in my hard drive (I kid you not, legit hundreds)_

 _To **Tears of Hearts** , yes most likely! It'll be a whole multi-chapter thing where all deleted scenes (coughSMUTcough) will be put, as well as the prequel to this (that is basically smut) and I'll post it on ao3 since __ff,net_ _doesn't technically allow smut._

 _Now on with the chapter!_

* * *

 ** _As the last syllable poured from the oldest demon's mouth, a figure made of smoke began to form._**

* * *

Yukio watched enraptured as the smoke shaped and coloured, from the feet up. A long, elaborate Victorian blue dress began to form, the heavy fabric shifting in the breeze of another plane of existence. Lace hemmed gloved hands flexed as they formed, elegant long silk gloves hiding the vicious claws that were most certainly there. The smoke formed blonde, almost white hair, hanging in a long braid. Finally, the smoke dissipated to show a young pale woman with distinctly pointed ears. She looked close to fourteen human years.

Mephisto panted slightly as he finished the summoning, staring intently at the summoned demon girl. Yukio was not terribly surprised to see the demon in such old fashioned clothes; he knew when humanoid demons were summoned that they often took on the appearance of their last host.

The girl turned slightly, surveying the room. Her pale lips turned down at the messiness of the room, clearly unimpressed. Her grey eyes passed over the desks, the strewn manga and the half eaten junk food, narrowing her eyes. She did not move, even though the circle was made only to restrict her to within it. The blonde's gaze fastened on Mephisto and her lips curled, revealing long fangs.

"Samael! I vought it might be you! Only un such as yourself 'ould summon me with no warnin'!" her quick look around had probably prompted her to guess she was in Japan, judging by her thick accent.

Mephisto raised his eyes to stare at her, green eyes burning holes, "You have improved in your Japanese since we last spoke."

"Ho?" she glanced around, frowning slightly at the blocked windows. "I am in Japan, no?"

"You are on my academy campus."

"Ah!" the girl said, smiling and began playing with her braid. "I 'eard tale from un of my clients that you'd founded an Assiah school!"

Mephisto nodded quickly, glancing back at the bed behind him. "I know it has been a while since your last... _visit,_ but it's urgent."

The demoness, stood up on her tip toes, looking intently at Rin who was being guarded by Mephisto. She frowned slightly, seeing his very human appearance. "Is zat my client?"

Mephisto nodded and the girl finally stepped forward. However, just before she crossed over the circle, her outstretched hand was scorched, the space it tried to cross over above the circle flashed blue. The girl retracted her gloved hand, cupping it to her chest. Her young teen's face crumpled into a malicious scowl. "Really Samael? I 'ought you wanted me to 'eal!"

Yukio shifted slightly in the doorway, moving slightly back into the office. He had no idea who this demon girl was only a few key factors: she was old and hadn't been summoned in a long while, she was healer and to speak to Mephisto in such a manor indicated she was either incredibly foolish, high standing or very powerful.

The white blonde whipped her head around at the rustle of fabric, looking like her neck was going to snap at the movement. Her eyes narrowed at the sight of Yukio, giving him a harsh look. "Who are 'o?" she growled, baring her fangs menacingly.

Mephisto snarled something in what sounded like German. The only thing that Yukio heard was his own name. The trapped demon pricked her elongated ears at the foreign words, her face falling into a sombre, almost sad expression. She said something, questioning, back in German. The demon King of Time shook his head. "Amaimon, why don't you stop hiding," he beckoned from over Yukio's shoulder.

From the corner of Yukio's eye, the green head demon in question slowly walked out from his hiding spot. He avoided the stare of the blonde and instead focused his eyes on Rin's still writhing form. The blonde sighed at that and turned back to look at Rin, "Zwat is 'is name?"

"He's Rin, Yukio's twin."

The demoness tilted her head at that, "Oh?" her eyes sparkled at the names, as though remembering something, suddenly her reservation gone, "Ze 'ung princelings?"

Mephisto merely nodded, his face starting to turn a sicklier white than usual. "He's sick and he needs assistance."

The demon woman shrugged, "Why 'ot take 'im to ey human 'octor?"

Amaimon slid closer to Yukio at Mephisto's next words, eyes glued fiercely to Rin.

"It's just like before."

The grey eyes widened, staring straight into the green ones. Her lips formed a small 'o' before she snapped it shut and began fumbling with her braid, looking irritated. "I'll 'eed a vessel. I can 'ot check 'im like zis!"

Mephisto nodded impatiently and began waving his hand. "Yes, yes I know! I'll get you a vessel for the necessary amount of time you'll need. Just-!" he took a deep breath, "Just tell me what I have to do for now."

"Keep 'im warm, ice on 'ead, don't leave alone, zots of 'ater... get me a 'ost quickly!" she snapped and Mephisto smeared his hand on to the chalked circle, smudging it.

With a whoosh, she vanished in a rush of smoke and Amaimon ran to Mephisto's side as he sank to the ground. Yukio stood still, stunned. Like before? What was that about?! Why did Amaimon look so scared of her?

Mephisto waved his hand and the requested materials appeared, worryingly for Yukio, without the demon's usual gaudy flair. Amaimon swooped the blanket out of his older brother's hands and began to wrap the worsening raven demon tightly, his usual blank expression hinting strain. Mephisto stood and began to wrap chips of ice into a cloth, placing it on the sweaty head.

Yukio, shocked and uncertain, stepped forward, "Who... who was she?" raising his voice slightly, "What is happening to Nii-san?"

Amaimon merely grunted as he pushed a cup of water to the younger demon's mouth, looking anxious. Mephisto stood up and sighed, "She keeps changing her name, but she's the most trusted physician in Gehenna. We don't know for sure what's happening... but if it is what I think..." the grim look on the King of Time unsettled Yukio, wishing to see that usual shit-eating grin again. He brushed past Yukio on his way to the door, giving him a slight pat on the shoulder, "I have to go find her a vessel. Stay here..."

Then he was gone.

Yukio slowly approached the bed to where Amaimon was hovering. Rin fidgeted within his tight blankets, face contorting in pain. Amaimon had taken to chewing on his nail, staring intently at Rin.

"Amaimon..."

The light eyed demon turned to stare at Yukio, the brunette realising that their blue eyes were incredibly similar. But unlike Yukio, Amaimon's eyes were much more feral, colder. Amaimon raised a thin eyebrow, demanding an answer.

"What... what is happening to Nii-san?"

It sickened him that he sounded so helpless. He was supposed to have a meister in Doctor dammnit! What was the point of gaining a meister like that if he couldn't even help his loved ones? And the fact that he had to rely on a demon for help...

Well, he thought bitterly, he was no longer human, if the fuzzy tail hidden under his shirt was any sign. He still couldn't fully accept that his humanity had been corroded away, leaving his demonic heritage to take control of his body. At least he had control over the blue flames now...

His green haired brother watched him, pausing in his gnawing. He glanced back at Rin, his gaze softening slightly; "If it's what Aniue thinks it is... then..." he began to chew with new a new-found ferociousness.

Yukio gulped, "What is it?"

"Hng?"

"What does Mephisto think is happening?"

Amaimon's eyes slid to Yukio, then back to Rin and then to the broken summoning circle on the floorboards. He paused once more before slowly shaking his head, reaching to give Rin some more water, "If it's true, then you'll find out. If it's a false alarm then we have no need to worry..."

Yukio was about to press him, when the door opened and Mephisto walked back in, leading a skimpily-clad woman. Yukio stared at the woman; she looked a little over eighteen. Faux ginger hair, sunken eyes, hallowed and pockmarked face, shivering despite the heater on; Mephisto had brought in a beyond deprecate street urchin.

The green eyed demon gave them a slight shrug as if to say 'she was the best I could find on short notice'. The woman behind him watched them, eyes fastening on Rin's sick form. "Look I'm gonna have to raise my price if _he's_ gonna be involved," she said jabbing her finger in Rin's direction.

Oh. He had hired a hooker to be the unwitting host for a demoness. Splendid.

However, the red head's only response was for Mephisto to pinch her neck. Her eyes rolled back and she collapsed to the floor, oh so conveniently in the middle of the circle. Mephisto ignored her and took out a fresh stick of chalk and began fixing the circle.

After the circle was mended, he came to stand beside the bed, looking at each of them in turn. The eldest demon sighed and rubbed the bridge of nose, "How troublesome..."

He began to chant and the pressure built for the second time that day. But instead of a figure made of smoke taking form, the wisps poured out of the circle's lines to cover the unconscious woman. She groaned and shifted onto her back as it began to coat and wrap around her, pouring into her skin and orifices.

Yukio shivered at the sight. He had seen on his missions, people become possessed and it was never a pleasant sight. But he had only seen demon's find the gap in people's hearts made by the decay of misdeeds, slipping inside like it was their own skin. He had never witnessed a forced possession, as it was punishable by death by the Vatican, but he had heard it was a most unsettling experience.

Now, as he watched the smoke thicken and begin to encase the hooker, he had little doubt that he was in for a show. The redhead screamed and arched her back, her hands clenching, toes curling. He remembered distantly of seeing an old exorcist movie by accident as a child, when flicking through channels. He had watched in horror as the actress had screamed and spazzamed, before Shirou had rushed in and switched the TV off. As long as her head didn't start to spin, Yukio wouldn't vomit.

The woman gurgled and choked on the smoke, a string of saliva sliding down the side of her make-up caked face. Her eyes rolled in her head as she gagged again before she was finally completely covered by the smog. There was a pause before it dissipated, leaving the redhead lying limp on the floor.

The room went deathly quiet, the tension hanging on whether it had been a success or not. Yukio held his breath, eyes darting over the limp human, searching for some sign of life.

There was a sigh of relief from all when the hand twitched and the woman sat up, jack-knife straight. Her eyes focused on them and her mouth curled in a smile, revealing small fangs. Springing to her feet, the she-demon began to inspect her new host body. She frowned as she touched her face, "You couldn't have gotten a prettier host?" she whined, all hint of her accent gone.

Mephisto glared at her and she sighed dramatically. "Lemme see him then!" and shooed them back to look at the raven haired demon. She poked his face, receiving only a disgruntled groan. Seeing them watching, she scowled and huffed, "It's gonna take a while to get an accurate diagnostic. Just leave, he's fine with me."

Mephisto nodded and steered the two younger, reluctant demons out and into the now accessible dorm hallway.

Yukio blinked at the harsh sunlight and immediately rounded on the two. "One of you better explain what is happening!" he hissed, "I do not appreciate being left out of the loop!"

Mephisto sighed and kneaded the bridge of his nose whilst Amaimon shifted uncomfortably.

"I won't be taking no for an answer."

Mephisto exhaled, his curl bobbing. He fixed his eyes on the youngest demon and Yukio felt himself wishing for the usual laughing, clowning Mephisto.

"Yukio... you know how demons are beings of nothing-ness?"

Yukio nodded and pushed his glasses up, causing the light to reflect. Of course he knew that! That was basic demonology! "I am aware of that."

Mephisto gave a mirthless smile, "Then you must also be aware that demons are majorly androgynous?"

"What?" Yukio took a sharp intake of breath. It made sense, now that Mephisto said it, demons not having a specific gender.

Mephisto gave a shrug, "Well that's half-true. We usually take after one or the other, with some having only minor or unusable additions. But there... are certain occasions when a male demon will have a..."

The brunette furrowed his brows confused. A what? What could he possibly mean? Yukio then paled, realising what he was getting at. "You don't mean to say...?!"

Amaimon gave a gruff snort, "Rin's pregnant."

Mephisto turned on him sharply, "we don't know for sure!"

"It's pretty obvious," Amaimon snarled and ripped off another nail in the process.

Yukio's lungs began to starve. His... his brother... pregnant? Could Rin, his twin, be carrying one of their children? It took all of his strength not to faint right there and then. No, there was no way! Swallowing, he fumbled with his tie, "But we're only half..."

Mephisto's face sobered and the next part was whispered, "That's why we're hoping it's only an intense fever."

Yukio jolted at that, "He's like this because of the-?!" oh god, he couldn't even form the word.

Mephisto nodded sombrely, "A fever like this often appears at the beginning... Especially since Rin's being overexerting himself so much these past couple of days..."

"Will... will he be alright?" this was beyond overwhelming; he was on the verge of blacking out. Rin was sick _and pregnant._ Oh god, oh god, what the fuck was happening?!

Mephisto nodded, eyes sliding to the closed door, "He should be fine, this illness passes quickly. The real test is at the end..."

Yukio took a deep breath, trying to steady himself, "What about the genetics?"

"Hmm?"

"We're all brothers, in case you haven't noticed, this is incest. The genetics are too close; it'll cause a defect, won't it?"

Mephisto shook his head, "No. Like I said before, demons are creatures of nothing-ness, we don't have genetics per say. When there are defective demon children, it is never due to incest."

Yukio felt a small sigh of relief. But then, he wondered, how did Mephsito know so much? Could they... could either him or Amaimon possibly have their own children? From previous partners? Voicing this, he watched the two shuffle uncomfortably. Mephisto glanced at Amaimon, before slowly shaking his head, "No. Neither of us have."

Even an idiot could see that there was definitely something more. Yukio was about to press, when the door opened and the healer demon poked her head out. Three pairs of eyes descended on her and she sighed, stepping out into the hallway.

"I've finished my examination and I've made sure he's on the road to recovery, he should be fighting fight by this afternoon."

"And? Is he...?"

The fake red-head sighed and ran her hand through greasy strands. All three knew the answer at that. Rin was pregnant. The half-demon was carrying one of their spawn and they didn't even now who. The healer stilled her hand and looked at them with a serious expression, "If... if all were to agree on it... it would be perfectly safe, maybe even for the better! I... I could, get rid of-"

"No!"

Yukio rounded on Amaimon, and was stunned to see the harsh, protective expression on the demon's usually unreadable face. Mephisto hissed and glared down at Amaimon, "Amaimon, I understand why you would refuse but-"

"No! We've got to at least try!" he snarled.

Yukio took a step forward, "Oi! Don't I get a say?!"

The demoness had found a carton of cigarettes in her host's pocket and was leaning up against the wall, watching them with the stick hanging from her mouth. "Iunno if you _should_ get a say, four eyes. You _might_ be the father but you don't know jack-shit about demon reproduction."

Amaimon glared at her, looking like he desperately wanted her to mind her own business. She ignored him and continued, "It's hard enough for a full demon to survive giving birth and both to survive, but for a halfing? You're just asking for both to die."

Yukio flinched at her wording. He was way out of his depth; his brother _pregnant_ , with a possibility of dying along with a baby which may or not be his.

Amaimon grabbed her by the neck and pinned her to the wall, eyes glinting. "But you can save them both, can't you?" she didn't respond, only aggravating the King of Earth more, " _Can't you?!"_

"I can try..." she then stared at Mephisto, "If all are to agree..." her eyes glided over to Yukio and then to the door where Rin was now resting.

Amaimon loosened his grip and the demoness began to walk down the hall. "I'll let you all talk it over. I'll need your answer by tomorrow if I'm to do anything or I'll go back to Gehenna," she called and disappeared down the stairs.

Yukio turned to look at his two older brothers, eyes burning with overwhelming confusion, anger and fear. "So...

"What is the decision?"

* * *

 _A/N: So yay this was shorter and less happened! Yukio was really hard to write for this damn it..._

 _Also Rin is pregnant (but you already knew that because of the summary). This fic is gonna be angsty in the beginning but there will be fluffy parts I swear..._

 _Also, I know the title is "demon baby daddy" but no one is going to be a dead-beat and leave Rin like the proper term for a baby daddy (it just gives it a nice ring)_

 _Reviews make me happy and give me motivation and inspiration (I waited until the first chapter got 300 views before posting. This has actually been ready to post for over a week but I like to keep things spaced and to have some prepared)._


	3. Decisions

Demon Baby Daddy

Chapter 3: Decisions

 _A/N: Lot of swearing in this chapter, just a heads up._

 _Also a big thank you to all the people who reviewed and have been giving me lot's of medical advice/suggestions/guides/tips about male pregnancies (and seahorses). I'll try to not stuff this up and anger the gods of reviews ehehe I make the joke *shot*_

 _BTW: no medical explanation this chapter ._

* * *

 **"I'll let you all talk it over. I'll need your answer by tomorrow if I'm to do anything or I'll go back to Gehenna," she called and disappeared down the stairs.**

 **Yukio turned to look at his two older brothers, eyes burning with overwhelming confusion, anger and fear. "So...**

 **"What is the decision?"**

 **(page break)**

The trio of demons stared at each other, all faces grim and set. They had to decide; should they let this baby be born? Amaimon growled and began chewing at his nail once more, thin eyebrows furrowing. Mephisto sighed and rubbed the bridge of his nose, obviously tired from such a high level summon and the situation at hand. Yukio adjusted his glasses, trying not to scream and take off running.

For who wouldn't go running when you got your older twin brother pregnant? Well, _he_ might not have, but it was still pretty messed up.

What the fuck was he supposed to do anyway?! He hadn't known until less than _five minutes ago_ that male demons could even _get pregnant!_ It had made his brother sick and according to the female demon and Mephisto, it was a high risk situation to both Rin and the – nope, he could barely even _think_ the word.

The three demons stood stock still, the air thick with tension.

"Why-" Yukio gulped when two pairs of reptilian eyes focused on him. "Why don't we ask Nii-san first?"

The two kings nodded reluctantly and the three of them stepped back into the dorm room. Rin was silent now, no longer writhing around and was breathing evenly. He even had a bit of colour already returning to his cheeks. The group shuffled closer and Rin flinched at the noise, blearily opening his eyes. He blinked and rubbed his eyes, groaning. "What is it?"

Yukio took a step forward, eyes darting to the two hovering demons, before schooling his face into neutrality. "Hey, Nii-san?"

"Hnng?"

"You were sick this morning; Mephisto had to get a healer," he said gently, crouching beside the bed where Rin looked at him with hazy eyes. "Are you feeling any better?"

Rin nodded and looked over to the two older demons. "Wassa matter?" he slurred. When no one answered except for down casting eyes, chewing on nails or averting their gaze, Rin sat up, suddenly wide awake. "What? What's wrong?! Am I still sick? Am I dying?!"

Yukio quickly shook his head, "No, you're not sick and you're not dying..."

"Then why are you all looking like I'm on my deathbed?!" Rin made to stand up but was hastily pushed down by Yukio.

The brunette demon took a deep breath, steeling himself. "Nii-san..."

"Come on moley four eyes! Spit it out!"

"You're pregnant."

There that should do it. It was short, blunt and to the point. No beating around the bush. Yukio didn't miss the sigh from Mephisto at his lack of tact. He got the message across, didn't he?

Or so he thought.

Rin frowned at him, "Come on Yukio, what is it?!"

Oh... he thought he was joking. Well, if he was in Rin's place, he probably wouldn't believe it either.

"I'm not joking, Nii-san. You really are pregnant."

Rin stared at him long and hard, the cogs ticking overtime in his brain. He glanced over at his two older mates, seeing only serious expressions. Rin had to admit, it was terribly convincing.

"Gwah!" he spluttered after a long moment, finally seeing they honestly believed him to be pregnant. "That's impossible! I'm a guy!"

Mephisto sighed and began to go through the whole 'demons are beings of nothingness so for some fucked up reason some male demons have wombs and can get pregnant, also we have no genetics' speech.

Rin stood there stunned at the end, looking not unlike a deer caught in headlights. So... he was pregnant. And there was a _somewhat_ logical explanation as to why... Huh.

Then it hit him with the force of a freight train when the words finally set it. _He was mothafucking_ _ **pregnant**_ _!_

He felt himself hit the mattress and blacked out for a moment. The raven haired was quickly revived (via drastic shaking) and he sat up straight, eyes wide.

"H-how do you know for sure?!" he stuttered, feeling overwhelmed. How the hell were these three so calm?! He was _pregnant!_

Mephisto glanced over to where Yukio had retreated to the wall and to Amaimon who was gnawing off a claw, seeing he was now responsible for the explanation. Turning back to Rin, he sighed for the umpteenth time that morning. "I summoned a physician from Gehenna and she confirmed it."

Rin began to tense up, his legs locking and his hands curling to fist his pants. His jaw set into a grimace and a ragged breath began to pass in between clenched teeth. Oh god, oh god, oh god, he fucked up, _he fucked up._

"S-s-so... do you know who the father is?" he squeaked, his face reddening slightly as memories of previous 'encounters' filled his head.

Mephisto shook his head, glancing at the two others. "No, we can't tell as of yet... it could be any of us honestly since it would be around now that demons who fell pregnant during the heat would show any signs."

Oh yeah, that's right. A goddamn _mating season_ for demons that happened only _once in one hundred and fifty years,_ had occurred just a little over a month ago, promptly ruining the family bond/friendship that they had going with _bloody hormones_ and shattering life as they knew it for the four of them _._ All four had been affected by it and had managed to only a bit over a day before the heat got the better of them and they very near attacked each other. After the season was over, the four could no longer revert back to their former friendship and so they had settled for an incestuous, demonic, polygamous relationship.

Just fantastic...

Rin gritted his teeth, starting to rock backwards and forwards. He was going to lose it, he was going to lose, oh god _he was going to go insane_. He may not be the brightest spark but even he could see that _this didn't sense_.

"But I'm only half! H-how?!"

Amaimon began to shift, sensing the conversation was drawing to its target. Mephisto glared at his green haired brother slightly before continuing, "That's why we've got to be careful about our next choice."

"Next... choice?"

Yukio glanced up to watch the oldest and second youngest demon's expressions. Amaimon stopped his chewing and stared, blue eyes burning holes. Mephisto looked Rin straight in the eyes, green reptilian meeting blue much more human orbs.

"You don't have to go through with it."

It was uttered so quietly, if it wasn't for their sensitive demonic hearing, they would have missed. Rin blinked, his face stilling as the words sunk in.

"The healer is still in Assiah. We're to give her an answer or she'll return to Gehenna." His eyes sharpened and his face almost became begging, the expression looking so incredibly strange on the proud King of Time, "Please think about this carefully. The chances of success are beyond low; the child or even you could die. I may like to gamble but this is something I don't want to bet on. And even if it does turn out fine and you both survive, what do you think will happen?"

Rin frowned and he bit his lip, nearly drawing blood with his sharpened teeth. What would happen, if a grandchild of Satan was born? There was a chance it would inherit the blue flames, especially if Yukio was the father. But if it wasn't it could inherit either Amaimon or Mephisto's power. Maybe even their own. But then...

"The Vatican would find out and we're already on thin enough ice as it is. There's even a chance that they would find out before the birth and will sentence you to death, not unlike how your own mother was condemned." The purple haired demon said stoically, trying to get the urgency of the situation across.

Amaimon growled and glared at Mephisto, "How can you say that when it could be your yours?! The Vatican may have hundreds of exorcists but all four of us are Gehenna princes! We'd work something out to protect Rin _and_ the baby! They might not know for years even if we do this right!" Amaimon turned to Rin, a fervent look in his eyes. "This is _your firstborn_ , don't give up on it!"

Mephisto turned to scowl down at Amaimon. He was never one to lose an argument, hated it more than Amaimon hated losing a physical fight. He especially disliked it when one of his mate's went against his wishes. Not that he was a control freak or anything, but he was the oldest and most powerful out of the four of them, he would know what was best shouldn't he?

Yukio glanced over to Rin who was looking beyond overwhelmed and absolutely terrified. "Nii-san," he said quietly, the dark blue eyes turning to him with wild, frightened eyes, "This is your decision, I won't pressure you to pick." Ok, that _may_ have been indirectly aimed at the two older demons to try and get them to back off. But Rin nodded weakly anyway, relaxing slightly. He was thankful that his twin at least would be supportive.

Amaimon had now nearly torn off all of his nails and was gnawing on his last one, eyes staring unnervingly at Rin. He almost didn't care what happened in the long run, he didn't even care if he was the one who got Rin pregnant, only that if Rin aborted; he doubted he would be able to stick around.

Mephisto tched when he saw the determined expression on his younger brother's face. Sometimes Amaimon's stubborn streak really pissed him off. Looking back at Rin he felt his old heart gave a slight wrench at the flame demon's scared expression. He did want Rin to have this baby, he honestly didn't care if it was his or not, but the risk was way too high. He doubted he could stick around if Rin was to die; he was too attached to the teen.

Rin took a deep shuddering breath and wrapped his arms around himself. Never, not in a million years, did he ever picture himself in this sort of situation. He felt like he was on the verge of passing out, or vomiting, or both. Oh good god, why him? Why did become pregnant, by his own brothers as well?

"I'll-" he stopped dead when the other demon's looked straight at him, eyes drilling holes. Was he going to give an answer? Keep it or rid it?

"C-can I think about it?"

Yukio nodded, "She said she'd be back tomorrow for our answer." He then looked pointedly at the other two and they all left the raven haired alone.

Rin flopped onto his bed and let out a groan, finally feeling like he could breathe. Pausing, he lifted his hand and rested it on his still flat stomach. He didn't know what he excepting, it was still too early for anything, maybe a kick or some form of movement. Of course there was nothing and Rin let his hands fall to the sides.

He frowned as he remembered a long time ago, back when he was much younger, of a woman coming to the church to seek guidance from Shirou Fujimoto.

* * *

Rin scuffed his sock into the floorboards, feeling bored. The monks were busy with their duties and Yukio was in the middle of book, asking not to be disturbed. He couldn't go outside either since it was raining.

 _Knock knock_

Rin looked up eyes wide, and darted to the doorway, "I'll get it!"

He opened the door and a pale woman stared down at him, bright green eyes widening at his sudden appearance and she asked hesitantly, "Is Reverend Fujimoto here? I have an appointment." She squeaked, rubbing the band of a bracelet. Oh, she was another one of those people who came to the church asking for help and advice from the priest. The little raven noted she looked a little older than the high school students who went to school next door to his elementary school.

Rin turned at the sound of his foster father's heavy footfall. "You're right on time," he said, giving the young woman a reassuring smile. He looked down at Rin and gestured for him to leave as the woman stepped inside the monastery.

Rin sighed and walked away, feeling slightly cheated. He was never allowed to be present at these advice giving meetings, and to his bored child mind, he was being deprived of entertainment.

Well then, he was going to be having none of that!

Ducking behind a doorway, he waited until he heard the tap of the office door being closed, before pressing his ear against said door.

"So what seems to be the trouble?"

"It's... I recently got out of a bad relationship, almost three months ago, and I've met this really great guy and I love him a lot, I even moved in with him last week. But..."

"Hmm?"

"I... I'm pregnant... from the last one... and I was wondering if I should have an abortion or go ahead with it. I'm scared that my boyfriend will leave me if he finds out and- oh!" Rin heard the sound of the woma choking up, "I just don't know what to do! I used to be against this sort of thing but now... Like it's mine also isn't it?"

Rin frowned as he tried to comprehend the woman's story. She was pregnant from a bad man, but she was with a good one now. He didn't know what the odd word was, "abortion," but it sounded serious. She was also very scared and confused.

He heard Shirou hum as he thought, he could still hear the woman's heavy breathing as she tried to stifle her terror.

"How sure are you that you're partner will leave you?"

"Huh?"

"You reckon he is a good man, so he will most likely support you no matter your decision, if he is as good as you seem to think he is. But, it would be wise to talk it over with him first, see his opinion on it. It is a huge step raising children; you need to know if you're both fit for it."

"Do you think it is alright in my situation?"

"You doubt if your relationship is stable right now to handle raising a child. Try and find what his reaction would be and move forward from there."

"I... I think I will try to do that, thank you."

"Feel free to come back if you need any further advice." Rin could practically hear the confident smile on the priest's face, the one that put all the troubled people who came to him at ease.

Rin pouted slightly. Usually these meetings would go on longer, probably with much more complex situations. Sometimes though, they were very short, like Shirou was merely pointing out what they would have decided all along. This seemed to be one of the short ones.

Rin darted up at the scrap of chairs and ran to his room and flopped on his bed, pretending to be idle. He heard the woman say her goodbyes before she disappeared back into the rain.

* * *

Rin exhaled as he finished reliving the memory. He had learnt later on what abortion meant, and the whole memory had taken on a sharper, more dramatic tone to it.

He could somewhat relate to that woman now. Rin had the supportive partner, Yukio, but he didn't know what the brunette's view on the situation was yet. Then, he had two demons pulling at him, much like the woman had two different views pulling at her. Mephisto thought the situation was too risky, that it would be safer to have it aborted. Amaimon, on the other hand, wanted to at least try.

Rin sighed and pulled the blankets tighter around him, starting the feel a headache come on.

He knew none of the three wanted it to end badly, only wanting Rin to be safe. That, possibly, made the situation worse and more painful, the 'I-only-want-what's-best-for-you' meant it was hard to keep everyone happy. With a deep breath and sinking gut, he made his decision. It was honestly a very stupid decision, but he couldn't bring himself to pick the other option.

With a groan, he pulled himself off his bed, feeling slightly dizzy. He had no recollection of the illness he had that morning; it must have been bad.

He shuffled down the hall, slid slightly on the stairs and made his way to the cafeteria where he could smell the others were, waiting for him. Three pairs of eyes descended on him as he entered and he gave a grimace, somewhat unnerved by the intense look in the three demons' eyes.

He just hoped they'd still be together when he gave his verdict. "I've made my decision.

"I'll keep it."

* * *

 _A/N: ok three chapters in and we finally get to the main part of the story! Whoosh, it's been heavy going writing this and we're just past the introduction! I plan to finish this definitely, but it'll probably take a good couple of months. ._

 _Also it looks like I'm heading towards a weekly update plan, but no promises._

 _Reviews make me happy._


	4. Differences

Demon Baby Daddy

Chapter 4: Differences

* * *

 **He just hoped they'd still be together when he gave his verdict. "I've made my decision.**

 **"I'll keep it."**

* * *

The room went deathly quiet as the words sunk in. Amaimon's face lit up and his cerulean eyes fastened on Rin, lips curling into an excited grin. Yukio merely nodded and exhaled, face set. Mephisto sighed and gave Rin a sharp glare.

"Are you _sure_ that is what you want?" The purple haired demon queried, staring the raven haired down.

Amaimon lost the happy expression instantly, rounded on Mephisto and opened his mouth to say something that he would definitely regret later. Rin, seeing the danger, quickly cut across, "I think we should try!" he paused, making sure that his green haired mate wouldn't snap at the oldest demon before continuing, "I think we'll be able to make this work out. Mephisto, you and the geezer kept me and Yukio hidden from the Vatican all those years; we could hide the baby as well!"

"Yes, but I'm more worried about you than the baby."

Rin gave Yukio a quick look for help and the bespectacled boy sighed. Turning to Mephisto, the bespectacled demon asked, "Didn't you say that the healer you brought in was the best?"

Mephisto grimaced and shook his head. "No, she's not the best, she's the most _trusted._ She has not once divulged any information on her clients, but remembers every last of her patients and all the times she has visited them before."

Amaimon began chewing on the short ends of his torn nails, glaring viciously. "But she'll be able to do this much."

Mephisto gave a slight shrug, "She has her moments."

Rin felt himself tense up. So Mephisto and Amaimon had both dealt with her? Apparently neither thought she was terribly good...

"Has she ever –" Yukio paused at he saw the tense look on both faces of the older demons' faces, "Has she ever _treated_ this sort of thing before?"

The King of Time shrugged, "Probably. It's beyond rare, but she would most likely be the first one to be called on." His lips quirked up a little, for he had done that himself hadn't he? "We know she won't tell of Rin's condition to anyone and if we offer enough then she'll stay to be on call for the duration."

Amaimon stopped in his chewing and looked thoughtfully at his long digits. "She may tell _someone_. She could hardly refuse if _he_ asked."

"Who?!" Rin demanded, feeling agitated by the sudden concern on his two older brothers' faces.

"Well, let's put it this way," Mephisto sighed and massaged his temples, "It is hard to withhold information from the King of Demons now isn't it?"

Oh god, they had forgotten Satan.

"I'm sure that _father_ would be absolutely delighted to hear of this development won't he?" Mephisto growled, sarcasm dripping.

Rin flinched, realising that the child would also become a target of possession and control by the Demon King. Yukio took a step forward, seeing his twin tense up and begin to close off. "Are you sure that you still want to go ahead with it?"

Rin nodded slowly. "I don't think I can bring myself to abort it."

Mephisto nodded and rose, replacing his top hat. "Then let the games of hiding and lying begin. Now if you excuse me, I must get several things in order if we are to proceed."

As soon as the door snapped shut, Amaimon leapt up and wrapped Rin up in a crushing hug, knocking the wind out of him.

"Hu-gh! A-Amai-! I-I can't breathe!"

The fire demon took great gulps as he was released and his green haired mate stared at him, blue eyes shining.

From the side, Yukio sighed and began to walk back up to the dorm room, muttering something about also needing work down. He himself might not be as close to the King of Earth as the others, but even he could tell that Amaimon wanted to alone with Rin for awhile. After all, he had gotten what he wanted, didn't he?

Rin laughed, slightly unnerved by the strong emotions in Amaimon's usually blank eyes. "I never really took you to be interested in having kids?"

Amaimon's lips twitched up, betraying how happy he was. "It's considered a great pride amongst demons to have your mate bear your offspring."

"Is that why Satan has ten sons?" Rin gave a little laugh.

Amaimon shrugged, a 'probably'. "Demons live a long time, sometimes forever. We don't have the same rush to produce and continue like the humans do-"

"Then why have the mating season at all?" Rin interrupted. It was the first time that they had properly talked about the season; they had avoided it in conversations after Mephisto had explained what exactly happened after the whole ordeal.

Amaimon shrugged, "Not all mate during the season, only if there is a suitable partner around... or _partners,_ " Rin remembered Amaimon had mentioned a while back that it was unusual, even with demons, to have this many partners at once, "But since we don't have to worry about passing on our genetics before old age, often enough demons take too long in picking partners before their demise..." Amaimon then frowned slightly, teeth gnashing.

Rin blinked, finding this conversation on demon culture oddly interesting. "What if a demon had a kid with someone other than their mate during the season?"

Amaimon wrapped an arm around Rin, pulling him closer, "On the odd chance that it does happen, the child is considered lesser than if it was with a recognised mate. Often enough anyway, demons find their mates through the season anyway." Amaimon said while nuzzling into Rin's neck.

"So the four of us are really considered each others mates?" Rin asked while nudging back.

Amaimon met his eyes, blue orbs burning. "Do you not see it that way yourself?"

Rin didn't miss how Amaimon's grip became tighter, more possessive and how he pressed himself closer to Rin. Rin quickly wrapped his arms around Amaimon, reassuring the green haired demon. "I do, just humans don't generally view this sort of relationship as legitimate."

"Who cares what humans think?"

"I do, as well as most likely Yukio and Mephisto since our current way of living is based off how we seem to humans." Rin sighed, thinking about how hard he had to struggle to show his friends he wasn't dangerous, how he will soon have to prove to the Vatican that he wasn't a threat. Now that he thought about, how was he going to hide this from them? Not that he really wanted, but it was a hard pill to swallow.

"That reminds me! How long do demon pregnancies go for?"

Amaimon looked up at him and blinked, "Depends on the species. How long do human ones go for?"

"Nine months."

"Hmm... probably around almost a year then."

Rin very near fainted. A year?! A year he'd be stuck being pregnant?! He had kinda hoped that it'd be shortened, but gees, a whole year?

Amaimon must have seen the look on his face because he quickly said, "I'm not really sure, it changes a lot depending on different factors."

"Like?!"

"Well..." Amaimon tapped his free hand on his chin, "If it's Mephisto's it might take a very short amount of time, a few months, or an extremely long amount of time, like maybe two years." Well, I guess things could go slightly haywire when one of your dads was the King of Time. "If its Yukio's then it might be more around the nine month mark."

"What if it's yours?" Rin asked curiously.

Amaimon shrugged. "Iunno. We can ask the healer when she get's back."

Rin blinked and titled his head, "What's her name by the way?"

"Dunno, she keeps changing it. Last time it was Alice, the time before that it was Charity." Rin had to hold himself from laughing. Charity? A demon called Charity?! _Pfft_. "She changes it depending on where she is and the trends. She said it helps hide and blend in. She's probably going around Japan right now listening in on conversations to find a new name."

They were interrupted however by a sharp click clack of claws and a telepathic, " _Rin!_ "

Amaimon drew back as the little Cait Sith came barrelling in. Kuro jumped straight into Rin's arms and snuggled in. " _Rin! I thought you were dying, I was so worried!_ "

"I'm fine, Kuro..."

Just before Rin realised that Amaimon was still in the room, Kuro gave a twitch and the cat demon leapt up onto his master's shoulder to snarl at Amaimon. " _Who are you?!_ "

Amaimon froze up and glared, "I'm Rin's mate."

Kuro narrowed his eyes and his claws came out to grip Rin's shoulder. " _I've never seen you before!"_

Amaimon raised an eyebrow and looked at Rin who was trying to detach the Cait Sith before he decided to turn into his large demonic form. "You haven't told your familiar?"

Rin shook his head and held the flailing demon in his arms, fully turning around now. "I thought we agreed to keep things quiet?"

"I told Behemoth."

"Behemoth can't talk."

"And who exactly would your familiar be talking to?"

Rin began stroking the horned head of the Cait Sith, trying to calm him down. He had a point. Rin had been so worried about Kuro exposing the relationship; he had forgotten that Kuro hardly talked to anyone besides Yukio and Rin. And they kept something like this from him...

He'd be counting his blessings if Kuro wasn't mad at him for this.

Oh well, at least try and reduce the damage...

"Ah Kuro, this is Amaimon, one of my mates. Amaimon this is Kuro, my familiar." He quickly introduced, faking a friendly tone.

" _One of your mates?! You have others?!"_

Oops...

"Y-yeah?"

Kuro turned to glare up at Rin, _"Do I know them?"_

Rin ignored Amaimon muttering something about how Behemoth would never be so rude, giving Kuro a weak smile as he pulled him back into his arms. "You know how sometimes, the dorm room is locked and there is only Yukio and me are inside?"

Kuro's little kitty mouth formed a small o and nodded, his form relaxing slightly at the realisation. _"So you and Yukio are also mates?"_

"And you know the principal?"

Kuro's eyes went wide. _"For how long has this being going on?!"_

"Since the heat."

Kuro looked at him bewildered and Rin remembered how not all demons became affected by the season. "A little over a month ago."

Kuro frowned slightly and placed a paw on Rin's chest from where he was being cradled, " _Why didn't you tell me?_ "

Rin grimaced and gently patted Kuro, "Uh... it's kinda hard to explain why but – we decided it'd be better if we kept things quiet. I see now I should have told you, I'm sorry, Kuro."

Kuro glanced over to Amaimon and frowned, yellow eyes showing distrust. " _Aren't you the King of Earth?"_

"I am."

Kuro's eyes widened and he yowled up at Rin, " _Rin! Wasn't he the one who attacked you a couple of months ago?! Didn't he get you exposed? I thought you hated him!"_

Oh. He had forgotten that he had ranted to Kuro shortly after the trial at the Vatican about how he hated Amaimon and how he was going to get revenge on him next time they met.

Well, that worked out didn't it?

"Yeah, but we've made up, I guess."

Kuro's twin tailed lashed as he glared at the Gehenna prince. " _So why are_ _you here now_?"

Amaimon stared stoically at Kuro, "Rin was sick this morning. Can't I visit my mate if he gets sick..." Rin paled when Amaimon's lips curled into a devious smirk, "Or pregnant?"

Kuro's jaw dropped for a second before being snapped shut and the black familiar turned on its master. " _You're pregnant?!"_

Rin shot Amaimon a dirty look before turning to Kuro with a pleading expression, "We found out just now! Kuro, please-!"

The Cait Sith jumped out his arms and leapt out the window, hissing.

"Kuro!"

Rin watched desperately as the Cait Sith disappeared down the pathway. Turning onto Amaimon, he yelled, "Why did you do that?!"

Amaimon pulled out a lollipop and swished it around his mouth, "He would've found out sometime."

"That was so tactless!" Rin growled and looked back at the empty road. "He shouldn't be shocked like that!"

Amaimon glanced at the ground. He didn't care that he had offended the cat demon, but he did care that Rin was now mad at him. He hated it when his mates were mad, especially at him.

"I'm sorry."

"No, you're not."

Rin sighed and rubbed his forehead. "I'm going to go find Kuro."

"He's just a familiar, why do you care? He'll come back."

Rin turned around, disbelief etched on his face, "Kuro is my _friend_. I care about him! Don't you care about Behemoth?"

Amaimon blinked and tilted his head, "Yes, of course I do. But Behemoth never questions me and would never run away. Familiars that get upset over not knowing every little detail of their master's life should have their contract annulled."

Rin shook his head furiously and stepped out.

"I guess that's where you and I also differ."

* * *

Kuro came to halt on top of the stairs that dotted True Cross Academy. He sat down and looked out over onto the campus. It was completely empty and quiet now, seeing as how it was the weekend.

He watched forlornly as the cars drifted past just outside the gates. He remembered once travelling far out, partially by accident, on the back of a motorbike. It had been just after he had a fight with Rin and he had gone to the grave of his old master. But now it seemed so trivial fighting over sukiyaki.

For a moment Kuro considered going back to Shirou's resting place but he shook his head. Rin had found him there before, he'd be there soon enough to see if Kuro had gone there. No, he needed to find somewhere else to hide.

Until when?

Kuro rose to his feet and began to pad around the school, golden eyes scanning the empty windows.

Until he decided where he stood on this matter.

* * *

Perhaps an hour after travelling around the campus, Kuro had somehow found himself high up on a walkway. He jumped onto the railing but seeing the dizzying height he was at, he quickly jumped back down. He looked around the walkway, starting to feel the stress of being lost.

"Kuro?"

Kuro spun around and was met with a little blonde girl. He gave a jolt when he remembered her to be the flowery smelling friend on Rin. What was her name again?

"What are you doing here?" she knelt down to look at him, big doll-eyes blinking. She was dressed in a kimono and had a heavy looking bag of what looked like supplies. Oh that's right, she worked in a shop didn't she?

 _"Rin lied to me..."_

Shiemi tilted her head, only hearing a quiet pitiful yowl from the cat. "Did you have a fight with Rin?"

Kuro nodded. He knew she couldn't understand him but he decided he should at least vent. _"He's mates with the King of Earth, the King of Time and Yukio! He didn't tell more for a whole month!"_ he hissed angrily, tail lashing.

Shiemi bit her lip. She had absolutely no idea what had angered Kuro (seeing as how Rin was involved, it could be anything) but she knew that Rin would be out looking for the Cait Sith. "Why don't you come back to my shop for a while?"

Kuro blanched slightly. He had not easily forgotten the disgusting herbal monstrosity she had served him. He gave a quivering mewl of 'I don't know...'

Shiemi gave him a reassuring smile. "Don't worry, I won't make you eat anything that I make." She had quickly learnt that, although her food was amazingly healthy, very few could stand eating it.

Kuro's little kitty face broke into a wide grin and he jumped up and down, feeling the relief wash over him. He was half worried that he would be having a repeat of when he had gone hungry like the time he had run away.

Following the girl, Kuro looked up and saw the little greenman spirit she had as a familiar. The green earth demon looked down and smiled toothlessly at him.

 _"Hello!"_

Kuro frowned slightly at it. He was in the fortunate spot where he could both talk to upper class – humanoid demons, and the much more simple-minded animalistic and plant-like demons (not that he particularly liked talking to them, they generally didn't have the most engaging of conversations).

 _"Hello..."_ He meowed back.

The little spirit waved an arm, little seed like eyes glistening in the sun. _"I'm called Nii!"_

 _"I'm Kuro."_

What exactly could greenmen do again? Create earthquakes? No... Manage gardens? No... oh! That's right! They could grow plants!

The little earth demon smiled, " _Let's be friends!"_

Ah, how nice a life it must be to be so naive and ignorant. Didn't Yukio once say something like: 'Ignorance is bliss'?

 _"Sure."_ Kuro meowed back at the demon.

They were interrupted by Shiemi climbing the stairs up to her home and entering. "I'm home!"

"Welcome back." responded a greying woman behind the counter. "Did you get the things I asked for?"

Shiemi nodded and lifted the heavy bag onto the table. She then gestured to Kuro, "This is my friend's familiar, Kuro. He just had a fight with his master. Is it alright he stay here for a while?"

Shiemi's mother leant over the desk to look down onto the little Cait Sith, eyes scanning.

 _"Hello ma'am."_ Kuro meowed up at her, trying to use his politest possible voice.

The woman shrugged. "Fine. As long as he doesn't cause too much of a ruckus or try and eat any of the items."

Kuro held back an angry yowl of how much more refined he was than that, back kept quiet. Better to not bite the hand that feeds him.

Shiemi smiled and began to pack away items. Nii hopped off her head and waddled over to Kuro. " _Hey, do you want to play?"_ the little spirit chirped, positively shaking with excitement.

Kuro nodded, glad for something to take his mind off Rin. " _What do you want to play?"_

Nii waved his arms around and swang himself up onto Kuro by the collar. " _Let's go to the gardens!"_ he shrieked and pointed to the door.

Following Nii's directions through the bushes, Kuro found himself in a beautiful garden, complete with a little stream and flowers. _"It's beautiful!"_

Nii leapt off and bounced on his stumpy little legs, little leaf hat (hair?) nearly falling off. _"Let's play hide and seek!"_

Kuro nodded, beginning to smile. The little black cat sith curled up, burying his head in his paws, ears twitching as he listened. He waited until he reached one hundred and twenty-one (his age) before leaping up to try and find the greenman amongst the plants.

Nii wasn't in the roses. He wasn't hiding in the herb patch. He wasn't hiding around the pots either. Kuro hummed and looked around, gold eyes scanning.

 **RUSTLE**

Over there! By the bushes!

Kuro bounded forward, kitty mouth pulling back into a smile. " _I found you!"_ he yowled.

However, it wasn't Nii in the bushes, but the absolute _least_ person he wanted to see. Kuro skidded to a halt, but didn't have enough time to run away before being scooped up by Amaimon.

* * *

 _A/N: (Excited screaming) Ok, ok, so my little odd fanfic has somehow become REALLY popular? If you're reading this, you probably only clicked on this story after the thought process, "_ _ **A YukioXMephistoXRinXAmaimon MPREG?**_ _Omg! I have to check this out! What kind of weirdo would ship this and write a mpreg for?" but uh yeah, I'm really happy that this has become so popular so quickly and uh yeah. Thank you!_

 _Reviews keep me motivated_ _and young and beautiful because I'm an egotistical demoness_


	5. Shocking news

Demon Baby Daddy

Chapter 5: Shocking news

 _A/N: So uh sorry if this chapter is kinda crappy, I had less time to edit it. I had a school camp that took up a good portion of the week (it was a lot of fun!) and I have recently watched Mirai Nikki (I'm more like Yuno than I like...) and I'm now really taken with Durarara (fairies, motorbikes, playful/flirty boys... there goes my kokoro [I'm not even ten episodes in yet!]) so watching those had taken up my time. I pumped this all out just yesterday._

 _I'm also going to be participating in Gratsu Week (it's a Fairy Tail ship fyi) so uh... that'll take up time too._

 _I'll try and keep up with this schedule I've been doing... My inspiration is low right now (and instead of trying to plot this story I keep thinking up an OC for Durarara... she is a god damn yandere send help) so... read on!_

* * *

 **However, it wasn't Nii in the bushes, but the absolute** ** _least_** **person he wanted to see. Kuro skidded to a halt, but didn't have enough time to run away before being scooped up by Amaimon.**

* * *

 _"_ _KYAA!"_ Kuro screamed and flailed, eyes going wide in horror.

"Hold still." The green haired demon growled, trying to restrain the Cait Sith against his body. "I'm no-"

 _"_ _Save me somebody!"_ Kuro howled.

"Kuro!"

Kuro nearly burst into tears of relief when Shiemi came galloping into the garden at the sound of the cat demon's screams, Nii clinging to her hair. She stopped however when she saw who was holding her friend's familiar. "You're-!"

Amaimon merely nodded towards her, expression blank. "Hello."

Shiemi's hand grasped the little summoning paper and her face hardened. "What do you want with Kuro!"

The greenette looked off to the side, mouth set into a thin line. He couldn't exactly tell her since then he'd have to explain why he was with Rin in order to be present for the fight... and also what the fight was about. "I'm... I'm taking him back to Ri-Okumura..." That was close... He used to just call him Okumura didn't he?

"I don't believe you!" she hissed, voice quivering slightly as she tried to come up with a strategy that could potentially win, with only a greenman to use.

Amaimon felt the Cait Sith slow in his struggling and prick his ears at his words. Now was his chance, before it started fighting again! "Goodbye..." and with that, he jumped with all his demonic power.

"W-wait! Nii-chan! I need something-anything!"

Amaimon took in a sharp gasp when he felt a thick thorned vine wrap around his left ankle and look down growling at the greenman that was struggling with the giant growth. Shiemi had kicked off her clogs and was determinedly attempting to climb up, trying to use the protruding thorns as footholds.

How annoying...

Amaimon watched her indecisively as she climbed. Kuro was leaning in his arms to watch the blonde wide-eyed, meowing down encouragement and instructions (not that she could understand it anyway). He could kill her but Rin and Mephisto would be beyond angry... he also couldn't just give her Kuro, that would seem too suss; it would lead to questions that would lead to confidential answers being uncovered...

"W-wait!" she called out, green eyes glaring in a... how would Mephisto put it? "Too-moe-to-be-scary"? Something like that. Anyway, she was hardly striking fear in the heart of the blue eyed demon prince.

Amaimon sighed and crouched down to the vine, digging his claws into the green. "Return."

 **POOF**

Shiemi shrieked and began to fall as the vine violently shot back into the greenman's stomach. Did she really expect to fight him with one of his own kin? She was just an Exwire, but even she must have known that a Demon King had control over their kin, right?

Oh... she might break if she hit the ground. He didn't need to bring attention to his brothers if the blonde girl was to die.

It was simple enough to swoop down and grab her arm before she hit the ground, proceeding to drop her onto her feet.

"You...?" She blinked her huge eyes at him in shock and Amaimon shifted slightly under her gaze, somewhat uncomfortable. "You saved me? But why?"

Amaimon felt himself stiffen. Shit, shit, he had to leave! She was frowning at him with complete confusion. He had to leave before she figured anything out!

"Ja."

 **WHOOSH**

"W-wait! Hold up!"

* * *

Rin wandered around the street, trying to see where the little Cait Sith could be. "Kuro! Kuro!" he harrumphed and continued searching. He felt guilty about not telling his familiar about his 'situation'... he honestly had no idea how we was going to make it up to Kuro when he found him...

"Rin..."

The raven-haired in question raised his head at the quiet shout and looked up to see a light green horn pointing over the edge of the building. "Amaimon? What are you doing up there?" Rin sighed, not quite forgetting the way that they had separated a few hours ago.

"I've got him." Amaimon said wide-eyed and shuffled forward to the edge to show he was holding a limp Kuro in his arms.

"KURO!" Rin screamed, instantly fearing the worst. His breath rushed out in a sigh of relief when one of the Cait Sith's hind leg gave a twitch and his ears flickered. He was alive... and fairly awake by the looks of it.

Amaimon landed with a thump next to him and passed the familiar over to Rin. "He kept on talking and asking questions so I put him to sleep..."

Rin gently cradled the cat and stroked the little horns; his shoulder's drooping in relief. "What about?"

How curious. Amaimon found it interesting how his black haired mate had faced many terrifying demons, demons from the royal family included, even Satan, and had exorcised them. Yet he showed pure and utter love for such an emotional little ball of fluff.

He'd make a great parent.

Amaimon felt his lips dug into a small smile. He wondered what tyrannical human he had killed in order to be this lucky. He took out a sucker and replied around the stick, "Us."  
Rin's head shot up, eyes wide. "Us?"

A nod. "Us. He wanted to know all about us, all four of us. He seemed to like the idea that we were on good terms before the heat. He wanted to know about how we were going to manage with the baby."

Rin smiled and nuzzled the little black cat in his arms. "Wow... Anything else?"

"He also said that he'd try his best to try and help with hiding and taking care of the baby."

Rin laughed and pulled the cat closer to his chest. "Atta boy Kuro!" Rin's eyes then travelled over to Amaimon and his eyebrows shot up when he saw the torn up leg warmer. "What happened?!"

Amaimon stopped on his lolly sucking and stared, brain trying to think of a reasonable explanation that didn't include the encounter with the blonde Exwire, not sure how his black haired mate would take it. "He... he struggled a bit when I found him..." the greenette was beyond thankful for the accelerated healing, for the cuts that had been there did not look a thing like cat scratches.

Rin's eyes widened, "You didn't get too badly hurt?"

"I survived being burnt by you; some cat scratches wouldn't affect me too much."

"Oh yeah, the whole demon king thing." Rin glanced at the sky and sighed. "I guess we should head back huh?"

Amaimon shrugged a 'sure' and the two began to walk back towards the old boy's dormitory.

* * *

The next morning, the four of the sat around in the mess hall waiting for the healer to come over.

Mephisto had explained that the previous day he had to begin preparing all sorts of charms and items to try and hide Rin... well actually the growing belly he'd soon be sporting. The purple haired demon explained that he was trying to make some sort of seal to hide the bulge from sight and deter others who weren't aware of the situation from touching the invisible space it would inhabit, without harming the unborn child.

"But it is taking longer than I expected. This sort of thing doesn't usually need to be hidden in this manner." Mephisto sighed, resting his head on his hand. "More often than not, the demon would just hide themselves away until the baby has been born. But in Rin's case, he's stuck in the spotlight and for him to go into hiding would be counter-productive. The Vatican would initiate a search and it would only be a matter of time before Rin would be found along with his predicament. It would also lead to Rin being executed along with the child, and the three of us would be closely watched, if not also to face similar punishment."

They were interrupted when the door swang open and the red-headed demon girl came in. She looked considerably better since the previous day. She was out of the provocative clothing and was wearing an obscure ensemble of clothes (that Rin and Yukio now realised was common amongst demons possessing) of a long skirt and turtleneck, accompanied by what was probably the host's entire jewellery box. She had bags under her eyes and had turned pale, probably from the strain on her body to maintain the demon inside. But she looked at least a little cleaner. "'Ello! Have ya made a decision?" she chirped.

Rin glanced back at his mates and bit his lip before turning back to her. "I'm going to keep it."

The demoness shrugged and leant onto one foot, eyes drifting towards Mephisto. He sighed and nodded, "We'll cover the cost of you staying to be on call."

A fangy grin spread across her face and she nodded. "Alright! I'll do checkups each week and you can summon me whenever ya need to. Now," her eyes darted to Rin. "Lemme just check on 'em!" and she, without even asking, ducked down and pressed her pointed ear to Rin's still flat stomach.

Rin looked confused over at his mates and Yukio watched bewildered. Amaimon was lurking against the wall, having silently moved away when she had entered the room. Mephisto sighed, "She's got good hearing."

"SHH!"

Rin stared in confusion at the mop of red hair pressed against him. He had no idea if it was possible to listen for a baby at this stage. Wasn't the child just noticed to be existing? But then again... they were demons.

The room was deathly quiet as they watched the demon woman's expression. She pressed herself harder against Rin and her lips turned to a thin line. Her brows knitted together and she pressed herself harder against his stomach, nearly pushing him backwards.

For a heart stopping moment, her face went completely still in shock.

Oh god, oh god, what happened?!

She withdrew very slowly, the hair falling over her face and she sat there, on the floor, looking confused. Then she raised her head, aggravatingly slow and whispered.

"There are three heartbeats."

* * *

 _A/N: Yeyeyeyeyehohohohoho! Are you all screaming, panicking, crying, freaking out? Aha I screwed you all over didn't I? Ehe, only one person, on ao3, guessed there might be triplets ahahahaha you poor souls who are reading this._

 _Also, I swear there will be an explanation in the next chapter as to why, for all the medical loving readers who are basically only here to see how I manage to explain a guy getting pregnant._

 _Finally, in case you didn't notice, at of all the possible ships of this OT4, AmaiRin is my fave aha ^q^ but I'll try and give more service to the other pairs and this OT4._


	6. Iyasu

Chapter 6: Iyasu

 _A/N: Look who decided to update her sorry ass. Especially after dropping that bomb in the last chapter. So basically the reason why I hadn't updated for months is simple. Once upon a time, a girl decided to get back into writing again. She launched into writing a mult-chapter and began to create a list of one-shots and other multi-chapters for her to write. Feeling proud, she increased her workload and created an Imagine blog on Tumblr. However, the girl soon realised she was drowning in things to write. She tried to complete the requests from the blog as well as complete the one-shot list but she could hardly keep her head above the pile._

 _So basically I've decided to come back for a short while to this story. I have over thirty things to write fyi and I just got a PS Vita so I'll be spending time playing that (I'M GETTING DANGAN RONPA YOU DON'T KNOW HOW LONG I'VE BEEN WAITING FOR THIS). I'm trying to post over 200,000 words by Christmas next year (I'm at roughly 33,000)._

 _Also, I've got bad writers block for this so I'm kind of forcing my way through this._

* * *

 **For a heart stopping moment, her face went completely still in shock.**

 **Oh god, oh god, what happened?!**

 **She withdrew very slowly, the hair falling over her face and she sat there, on the floor, looking confused. Then she raised her head, aggravatingly slow and whispered.**

 **"There are three heartbeats."**

* * *

The room went dead silent as the words sunk in. No. That couldn't be right. The demoness began to chew on her lip, stressed. She started fiddling with the numerous bangles and bracelets, looking for all the world lost. She was muttering a string of guttural words; probably whatever was spoken in Gehenna, but it sounded like confused babble.

Amaimon had moved closer, blue eyes watching creepily. Yukio was frozen stiff, sure that he had heard wrong. Mephisto had only sighed deeply and leant back. Rin felt like he was suffocating.

No, no, no. This wasn't happening. How could it? She must have gotten it wrong. No way could-

"What..."

The redhead's head snapped up, eyes staring. "Hah?"

Rin flinched. Finally, he chocked out, "What... what did you say?"

The demoness hummed discontented and rubbed her scalp. "Fuck if I know what's happening. This shit hasn't happened before." She gritted her teeth and whined. "This is _so_ messed up!"

'Like you're one to talk' Rin wanted to scream.

Rin glanced around, eyes desperately searching the others for help but seeing none. Amaimon was poised behind the table, looking ready to rip the healer to pieces if she so much as breathed wrong. 'Tired' was an understatement to describe Mephisto. Yukio was still rigid, glasses beginning to slide down his nose.

Desperately looking around, Rin began to rock. No, no. This was too much. He had kind of (not really) come to terms with the fact that he was pregnant with one demon child; but with three? No, no way. This couldn't be happening. This had to be some kind of _really_ sick joke.

The redhead began pulling at the ends of her hair and gritting her fangs. "Male pregnancy is so rare that..." she gave a strangled groan, "there has never been multiple! Oh-! What am I gonna do? It'll be hard for me to handle making sure all four survive!"

"Like you're one to talk! You're not the one having them!" Rin yelled, nails digging into his arm.

The demoness snapped out of her reverie and scowled, but was quickly cut short by Yukio butting in. "Does that mean all three might be ours? As in – there is one for each of us?"

The demoness paused and hummed, "Probably. It would explain how there's three – since there are three of you." She turned and stared out the window eyes glazing over, "A demon becomes fertile during the heat and since we... hmm... you know how with cats – a queen can have kittens from multiple different fathers? It's like that with demons."

"Demons can't become reproduce otherwise?" Yukio asked, his glasses flashing at this piece of information. Information on demon reproduction for exorcists was scattered and there were many different theories on it but very little proven.

The demoness shrugged. "Pretty much. The heat actually goes for a year but it affects different demon species at different times throughout for about a week. Bu there are some species that their reproduction rate is so low in general that they are almost fertile throughout the whole year. Though..." she stopped and chewed her lip, blood tricking down from where she pricked it with her fangs. "We can still have sex but no eggs if it's not during the heat." She shrugged again.

"I've also been meaning to ask, but how exactly is my brother supposed to give birth?" Yukio asked, seeming to forget the other three as he learnt what no other human had probably had heard about before.

The demoness' eyes sparkled as she realized that there was someone genuinely interested in how she did her work. It seemed human or not, it was still appreciated when others took interest in their line of work. Smiling with arrogant pride, the demoness tapped her claws on the floor. "With female demons, I can do it 'naturally' but with male demons I do a caesarean." She gave a smile at Rin's pale face and followed his gave to her sharp nails, eyes sparkling morbidly. "Don't worry. I'll be using proper utensils – less hassle to clean up."

Seeing Yukio open his mouth to ask another question she gave a wiggle of her finger, face lit up, "I know what you're gonna ask. 'How did he get pregnant in the first place? Shouldn't he have a womb and ovaries?' right?" she grinned as the bespectacled half-demon nodded, "For one – demons don't have ovaries since that's something only creatures with a biological clock have. During the heat, provided a demon has a womb, hormones will create eggs to be fertilised in the event of sex – kinda going back to the thing with cats with how queens will ovulate once they've mated.

"As to how exactly did the sperm get there? Well, no one knows! The womb isn't connected to anything in male demons so I assume that there are roots or something to soak it up and transport it to the womb. But each species is different so it's hard to know. And that's all you wanted to know right?"

Yukio nodded slowly, not sure if he trusted her explanation (roots?) and the demoness sighed. "You lot have got a case never head of – even amongst demons. Incest, polygamy, male pregnancy with multiple babies from each partner?" she grinned maliciously, "how sinful~!"

Rin was sure he definitely didn't like this demon. He knew she was supposed to be the one who would make sure he'd survive the whole ordeal but she just seemed so... sadistic? No, nearly every demon was sadistic. She was 'I like to watch awkward situations to see people squirm' sadistic.

The demoness popped to her feet and sighed, tilting her head. "I'm gonna have to leave right now if I'm going to get everything for next week's exam..." she began to drift towards the door but stopped dead when she saw the dark expression on Mephisto's face.

"Are all three fine?"

She blinked and nodded, all trace of gaiety gone and Mephisto gave a slight scowl. "You'll be wanting a pay increase for this, won't you?"

She glanced to the side, looking edgy at the intense look. "I suppose that'd be fair..."

"Fine." The demon King of Time threw her a small satchel that had suddenly been at his side.

The crushed black velvet bag landed easily in her hands and her pale face positively lit up. "You're too kind~!" she sighed, hugging the bag close. Rin could smell something rotting sweet from the inside it. He dared not think too deeply as to what it could possibly be.

Mephisto fell back into his usual pose and the same mocking tone entered his voice again. "So what name do you go by this time?"

The redhead paused and tilted her head, tapping her chin. "I think I'll be Iyasu. It means healer right?" without waiting for a response she turned and began to trot out the door, "Bye!"

The room become visibly less tense when she disappeared and a rush of tired sighs resounded.

"Well... things have certainly become more complicated than before, ne?"

* * *

 _A/N: I'll probably update after posting three one-shots. If you're on ff,net then I might seem kinda inactive but that's because I've been posting more on ao3 (because ffnet doesn't like smut)._


	7. Chapter 7

So basically:

Short: This is going on probably permanent hiatus

Long: So I haven't been in the Blue Exorcist fandom for a LONG while and I've been pretty unimpressed with the recent chapters so I haven't felt any real drive towards this story rather than guilt to finish. I'm stuck with writers block and I have tried to complete the seventh chapter but it's felt more like a chore rather than something I enjoy doing. I'd much rather start working on other stories than something I'm deriving no pleasure from. I'm terribly sorry for all those that have tried to stick with me on this and for the newcomers who have just started following this. I may come back to this eventually but the chances are unlikely. Please understand my decision; writing is something I enjoy and am proud of, but it's a process to make a chapter and if I'm not doing it with flow and joy, it can take me weeks to produce just a few finished thousands words. I will most likely keep this story online since I really do appreciate all your comments and support.

Thank you.


	8. Chapter 8

So this long and the short is: Demon Baby has gotten a revival!

It's being done by ShadowTrooper1414 on fanfiction,net and they recently posted the first chapter! I'm excited to see where they take where they take this story! The only difference, is Rin's female.

So, yeah, go and follow/fave it (I know I am): www,fanfiction,net/s/12343452/1/Demon-Baby-Daddy-s (change the commas to full stops – changed for ff's finickyness.)


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